Thread protector



June 1, 1937. D. s. BOWERS THREAD PROTECTOR 2 Sheets-Sheei 1 INVENTOR 00 .5. flowers BY Filed Aug. 10, 1936 ATToRriEY Patented June I, 1937 UNITED STATES PATENT OFFICE 2,082,144 THREAD PRoTEcToR Don S. Bowers, Tulsa, Okla.

Application August 10, 1936, Serial No. 95,122

4 Claims.

This invention relates to thread protectors and more particularly to protectors for the threaded box and pin joint ends of sucker rods and the like.

Sucker rods are used in pumping fluids from wells, and in oil well practice, for example, the

wells vary greatly in depth. In all pumping wells, however, the strain on the sucker rods is severe due to the weight of the rods themselves and the oil being lifted from the well. It is ap parent that care must be taken to protect the threads of joint ends of the sucker rods in order to expedite the rapid assembly thereof and to obtain a close and secure fit between the several rods. The responsibility for the'care of the sucker rods has devolved somewhat upon the manufacturers of whom rigid requirements are exacted by the trade to assure delivery of the sucker rods in good condition.

The principal objects of the present invention are, therefore, to provide means for fully protecting the externally threaded pin and internally threaded box endsof sucker rods, as well as couplings therefor, from corrosion, abrasion, bruising and accumulation of dirt while the sucker rods are being stored or shipped either before or after use in a particular well; to provide means for sealing the threaded box and pins from the atmosphere and elements; and to provide means for maintaining lubricant in contact with the threaded ends of the rods for further protecting the threaded ends of the rods from oxidation.

In accomplishing these and other objects of 5 the present invention, 1 have provided improved details of structure, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a perspective view of the pin end of a sucker rod provided with a thread protector embodying the features of the present invention.

g Fig. 2 is a detail perspective view of the pin and thread protector illustrated in Fig. 1 shown in disassembled relation to better illustrate the invention.

Fig. 3 is an elevational view of the pin end of the sucker rod provided with a thread protector, the protector being shown in cross section to illustrate its assembly relative to the pin.

Fig. 4 is a horizontal cross section of the line 4-4, Fig. 3.

Fig. 5 is a horizontal cross section on the line 5-5, Fig. 3.

Fig. 6 is a perspective view of the box end of 55 a sucker rod provided with a thread protector embodying the features of the present invention.

Fig. '7 is a detail perspective view of the box end of a sucker rod and thread protector shown in disassembled relation to better illustrate the invention. r

Fig. 8 is anelevational view of the box end of the sucker rod provided with a thread protector, the protector being shown in cross section to illustrate its assembly relative to the box end of the sucker rod.

Fig. 9 is a bottom perspective view of a modified form of a box end of a sucker rod coupling.

Fig. 10 is a horizontal cross section on the line H!l0, Fig. 9.

Referring more in detail to thedrawings:

I designates a sucker rod of the type used in pumping oil from Wells, which is flanged outwardly adjacent one end as at 2 in Figs. 1, 2 and 3, slightly reduced above the flange 2 and then squared as at 3 to provide a wrench head for turning the sucker rod, when desired, by use of a suitable wrench, not shown.

One end, for example the pin end 4, of the sucker rod is upwardly and outwardly tapered above the squared wrench head to provide a flange 5 having a shoulder 6 on the upper face thereof. Extending vertically above the shoulder 6 in slightly inwardly offset relation thereto is an upwardly and inwardly tapered pin 1 provided with threads 8. A cup 9 is provided, which is preferablycylim drical in shape and of suitable metal construction, having a closed end to. The cup is of a size adapted to be sleeved over the pin 1' to cover and protect the threads thereof as shown in Fig. 3. Spaced from the closed end ll] of the cup is a shoulder H substantially correspondingin width to the shoulder 6 of the sucker rod and adapted. to seat thereon. The shoulder Ill is preferably formed integrally with the cup 8 and, is provided with a skirt l2 extending downwardly over the flange 5. The skirt I2 is provided with clamping lugs l3 which are preferably four in number adapted to be bent under the flange 5 on the taper thereof to hold the cup in place about the pin and thereby protect the threads of the pin end of the sucker rod.

While the cup as described protects the threads of the sucker rod from abrasion and bruising, when the rods are stored or shipped moisture and dirt are apt to accumulate in the cup around the threads. Such an accumulation in conjunction with atmospheric elements corrodes and clogs the threads and the sucker rods must thereafter either be cleaned before use or discarded altogether.

To obviate such accumulation I interpose a washer I4 of felt, foil or other suitable material between the shoulder 6 of the sucker rod flange and the shoulder l l of the cup in such a manner that moisture and air are excluded from the interior of the cup, when the cupis clamped to the pin, thereby avoiding contact with the threads of the pin end of the sucker rod, and consequently preventing corrosion and clogging thereof.

It is also apparent that the interior of the cup may be coated with grease for contact with' the threads of the pin to further protect the threads from oxidation and, further, to seal off atmospheric elements from the interior of the cup. j

In Figs. 6 to 8, inclusive, I have shown the box end l5 of a sucker rod 16 which is provided with a flange ll and a squared wrench head l8 similar to that shown in Figs; 1 to 3. The box end of the sucker rod is also provided with a peripheral flange 19 above the wrench head from which the box 20 is extended in vertical alignment therewith, a distance substantially corresponding to the length of the pin 1. The box is bored at the outer face 2| thereof and provided with internal threads adapted to fit the external threads of the pin 1 whereby the pin of one sucker rod may be joined in the box of another sucker rod to build up a string of rods.

While the threads of the box end of the sucker rod are partially protected from bruising and abrasion by reason of their being on the inside of the box, moisture and dirt may collect therein to corrode'and clog the threads.

In overcoming this difficulty I provide the cylindrical cup 22, formed of material similar to the cup 9, which is of a size suitable to fit over the box end IQ of the sucker rod, the cup 22 having a closed end 24 to cover the bored end of the box. 7

As in the cup shown for the pin end ofthe sucker rod, clamping lugs 25 of any suitable number are provided at the open end of the cylinder which are adapted to be turned under the flange l 9 for holding the cup in position in the box.

A washer 26 of felt, foil, orother suitable material is also interposed between the outer end 2| of the box and the-closed end 24 of the cylinder, concentrically of the threaded end of the box for preventing seepage of moisturefor accumulation of dirt into the spaces between the threads of the box.

In Figs. 9 and 10, I have shown a modified form of coupling 21 for the joint ends of sucker rods, wherein a pair of flattened sides 28 are provided to form a wrench head. In case such a sucker rod coupling is shipped or stored, only two clamping lugs 29 need be provided on the box end type of cylindrical cup for bending under the shoulder 30, left by the flattening operation on the sides of the wrench head, to hold the cup in position.

In applying the cups to the joint ends of sucker rods, it is apparent that the type shown in Figs. 1 to 3 is for use on the pin ends thereof and which, after a washer has been placed on the shoulder 6, may be merely sleeved over the pin and clamped thereto by manually, or otherwise, bending the lugs under the flange above the wrench head. The type of cup shown in Figs. 6 to 9 is also merely sleeved over the box end of the sucker rod, or coupling, after placing the washer 26 on the ,end 2| of the box or inrthe cup itself, and clamped thereto in a manner similar to thatfor the pin end cups.

What I claim and desire to secure by Letters Patent is: i

l. A device of the character described including a cup adapted to be sleeved over the ends of a sucker rod having clamping lugs at one end adapted to engage portions of said sucker rod for securing the cup tothe rod, and means interposed between said cup and sucker rod for sealing the interior of said cup.

2 A thread protector for the pin end of a sucker rod includinga cuphaving a shoulder seating ona shoulder of said rod below said pin end and having lugs clampingly engagable with said rod for retaining the cup on said end.

- 3. A thread protector for the pin end of a sucker rod including a cup having a shoulder seating on a shoulder of said rod below said pin end and having lugs clampingly engageable with portions of said rod forretaining the cup on said end, and means interposed betweensaid shoulders for excluding moisture and dirt from said cup.

4. A thread protector for the pin end of a sucker rod including a cup having a shoulder seating on a shoulder of said rod below said pin end and having a skirt extending toward a wrench head on said rod, lugs on said skirt clampingly engageable with said rod for retaining the cup 

